Supportive Treatment

TREATMENT

GENERAL MEASURES

Pregnancy

Pregnancy remains associated with a substantial mortality rate in PAH. Although recent data suggest that, in selected patients, the outcome of pregnancy in PAH may have improved, there is insufficient evidence to alter the recommendation that it should be avoided.

Contraception

Dual methods of contraception are recommended:

A progesterone only oral contraceptive pill OR intrauterine device.
Barrier contraception.

To reduce the risk of venous thromboembolism, the combined oestrogen-progesterone contraceptive pill is not recommended. Bosentan may reduce the efficacy of the progesterone only pill. Therefore, barrier contraception in this setting is imperative.

Exercise and
rehabilitation

Patients are advised to remain active and exercise within their symptom limits. Exercise which causes severe breathlessness, dizziness or chest pain should be avoided.

Supervised exercise training programs run in specialist PH centres have been shown to be safe and to improve quality of life and exercise capacity. Further research is needed to determine the optimal components, intensity and duration of PH specific rehabilitation programs.

Vaccination

As with other chronic health conditions, pneumonia is a significant cause of morbidity and mortality in patients with PAH. Pneumococcal and annual influenza vaccinations are recommended.

Elective surgery

In general, patients with PAH tolerate anaesthesia poorly and spinal anaesthesia is recommended over general anaesthesia. Patients maintained on oral therapy may require short-term conversion to intravenous or nebulised therapy until they can safely swallow and absorb oral medication.

Drugs to avoid

Nitrates should be avoided in PAH, particularly if the patient is on a PDE5i. This combination can cause dangerous hypotension. Beta-blockers are poorly tolerated as patients with PAH rely on the ability to increase heart rate to maintain cardiac output. Cyclizine causes increases in pulmonary artery pressure and should not be prescribed.

Atrial fibrillation / flutter

Atrial dysrhythmias can cause significant decompensation. Electrical cardioversion with adequate anticoagulation is the optimal management for atrial fibrillation. Digoxin may be used as an alternative. Beta-blockers should not be prescribed. Ablation by cardiac electrophysiology is the optimum management for atrial flutter.

SUPPORTIVE THERAPIES

Diuretic therapy

Diuretics are recommended in patients with clinical features of right ventricular failure or volume overload. In some cases, intravenous diuretics are required. Serum biochemistry should be monitored on a regular basis.

Oxygen supplementation

Alveolar hypoxia is a potent pulmonary vasoconstrictor, leading to increased pulmonary arterial pressure both acutely and chronically. Oxygen supplementation is recommended to maintain PaO2 > 8kPa (60mmHg) at rest. In flight oxygen is recommended for WHO functional class III or IV. Patients in FC I-II with saturations between 92-95% should have a hypoxic challenge test. Similarly, patients who fulfil these criteria should avoid altitudes greater than 1500-2000m.

Cardiac glycosides

The role of cardiac glycosides in PAH is unclear and has not been the subject of a randomized controlled trial. Digoxin may be considered in patients who develop an atrial tachyarrhythmia in order to slow ventricular rate. No evidence exists to evaluate their long-term effectiveness.

Anticoagulation

Evidence on benefit of anticoagulation in idiopathic, heritable and anorexigen associated-PAH is conflicting. Anticoagulation (aiming for an INR of 2-3 if warfarin is used) should be considered on a case-by-case basis. Anticoagulation therapy is not recommended in associated forms of PAH unless there are other indications.

Calcium channel blockers (CCB)

The appropriate use of CCBs in patients with IPAH is controversial. Concern exists that CCB therapy in non-responders may further impair cardiac function. Treatment of IPAH with CCBs is reserved for patients in functional class II who demonstrate evidence of acute vasoreactivity, defined as a reduction in mean pulmonary artery pressure >=10mmHg to a level that is <=40mmHg, with an increased or unchanged cardiac output during testing with an acute, short acting vasodilator. Inhaled nitric oxide is the vasodilator of choice. The choice of agent is dependent on heart rate, with relative bradycardia favouring amlodipine and relative tachycardia favouring diltiazem. Both should be started at a low dose and titrated up. Response to therapy should be assessed at 3-4 months and re-evaluated if no benefit or clinical worsening is seen.